barrow-boy vs monger

barrow-boy and monger both are nouns.

Word	Noun	Adjective	Verb	Adverb
barrow-boy	Yes	No	No	No
monger	Yes	No	Yes	No

As nouns, monger is a hypernym of barrow-boy; that is, monger is a word with a broader meaning than barrow-boy:

barrow-boy: a hawker of fruit and vegetables from a barrow
monger: someone who purchases and maintains an inventory of goods to be sold

Other hypernyms of barrow-boy include bargainer, dealer, trader.

barrow-boy (noun)	monger (noun)
a hawker of fruit and vegetables from a barrow	someone who purchases and maintains an inventory of goods to be sold

barrow-boy (verb)	monger (verb)
	sell or offer for sale from place to place